A multi media card (MMC) is a popular memory card used in portable host devices such as cell phones, digital cameras, personal digital assistants (PDAs), global positioning systems (GPSs), digital audio players, digital video games, etc.
The conventional MMC system specification version 3.xx defines the MMC as a memory card with a form factor of 32 mm×24 mm×1.4 mm, and 7-pin contacts for electrical connection to a host. The MMC includes of a flash controller and a flash memory device. At an operating frequency of 20 Mhz the host is able to access the MMC with a transfer speed of 20 Mhz×1-bit=20 Mb/s=2.5 MB/s for both read and write operations.
However, the conventional MMC in the market performs read operations at speeds lower than 2 MB/s and write operations at speeds even lower than 1 MB/s. The flash controller performance clearly has room to be optimized to raise the transfer rate.
Due to a higher transfer rate requirement from host devices, the MMC system specification 4.0 has updated the MMC with 4-bit and 8-bit options in addition to the original 1-bit host data bus. With the wider host bus, the host transfer rate is further increased substantially, for example:                Transfer Rate (4 bits, at 20 Mhz)=20 Mhz×4 bits=80 Mb/s=10 MB/s,        Transfer Rate (8 bits, at 20 Mhz)=20 Mhz×8 bits=160 Mb/s=20 MB/s.A problem with the conventional MMCs is that it uses a conventional flash controller, which has a throughput that does not match the capability of the host bus.        
Accordingly, what is needed is an improved flash memory system, which includes a high-speed flash controller that overcomes the above-identified problems. The present invention addresses such a need.